/sys$common/syshlp/helplib.hlb MACRO, VAX MACRO Assembler, Instructions, Bxxxx  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Branch - test condition code(s)
    Format:         opcode displ.bb
    Operation:      if {condition} then PC = {PC + SEXT (displ)}
    C. Codes:       Not affected
    Exceptions:     None
    Opcodes:        12 {Z EQL 0}        BNEQ  Branch not equal (s)
                                        BNEQU Branch not equal (u)
                    13 {Z EQL 1}        BEQL  Branch equal (s)
                                        BEQLU Branch equal (u)
                    14 {(N OR Z) EQL 0} BGTR  Branch greater than (s)
                    15 {(N OR Z) EQL 1} BLEQ  Branch less or equal (s)
                    18 {N EQL 0}        BGEQ  Branch greater, equal (s)
                    19 {N EQL 1}        BLSS  Branch less than (s)
                    1A {(C OR Z) EQL 0} BGTRU Branch greater than (u)
                    1B {(C OR Z) EQL 1} BLEQU Branch less or equal (u)
                    1C {V EQL 0}        BVC   Branch overflow clear
                    1D {V EQL 1}        BVS   Branch overflow set
                    1E {C EQL 0}        BGEQU Branch greater, equal (u)
                                        BCC   Branch carry clear
                    1F {C EQL 1}        BLSSU Branch less than (u)
                                        BCS   Branch carry set
                    legend: s - signed, u - unsigned
    Description:    The condition codes are tested and if the condition
                    indicated by the instruction is met, the sign
                    extended branch displacement is added to the PC.